thermostat ?

[acme]

Late 80's Johnson 90hp V4. After the engine warms up, hte tell tale stream is hot for a couple of seconds then cold a couple seconds in a repeating pattern.<br /><br />I don't think this is normal. Could it be something wrong w/ the thermostats? <br /><br />Thanks.

 

[almost retired again]

Re: thermostat ?

Hi Acme,<br />Is your engine over heating? I don't think that it's normal for the thermostats to open and close that quickly, but if the engine isn't over heating I don't see a problem. However if it's worrying you replace them and see what happens.

 

[acme]

Re: thermostat ?

Thanks Retired,<br /><br />I can't tell if its overheating (no warning horn). But I'll try to find temperature stick. Then replace the thermostats if needed. <br /><br />It should be fun trying to get those thermos out without taking the whole head off!

 

[oldboat1]

Re: thermostat ?

You can check to see if it is overheating by carefully putting your hand (side of your hand or fingers you rarely use anyway...) on the top of the head or between the cylinders. You should be able to hold your hand there for a few seconds. If it's too hot to touch, it's running hot. Don't burn yourself.

 

[kart33]

Re: thermostat ?

I have an 85 90HP evinrude. It sat up for 3 Years before I got it and the thermostats were Corroded beyond opening. 4 bolts on the bottom of the power head between the cylinders and 20 bucks and your good to go. Mine did exactly the same thing, there are 2 relief valves in the housing that are opening to relieve the pressure when hot and then the cold water circulates thus the hot cold hot senerio. Good luck

 

[acme]

Re: thermostat ?

Great, I knew there was somone who has had this problem. <br /><br />Thanks for the help.

 

[Solittle]

Re: thermostat ?

Just finished doing my 1988 1.6L Sea drives. There is a lot of info available on this site on the "how to's." Try the Search function to get all the info.<br /><br />My "mechanic" told me that my powerheads had to come off to get to the thermostat housing and that would be $250.00 in labor - thank you very much. Well that $250.00 never left my pocket. Only tricky thing on mine was keeping everything together when reassembling. I used sealer 1000 and rubber bands till I got the bolts started.

 

[DJ]

Re: thermostat ?

acme,<br /><br />It helps a great deal if you loosen all the bolts that hold up the lower pan on the engine. You will also have to remove the plastic surround on the top of the exhaust housing under the lower pan.<br /><br />It gives you a couple more inches to aid in disassembly and assembly.<br /><br />Make sure you note how everything comes apart. When you go to put it back together, you'll swear those cork gaskets don't go where they go.